JP7035707B2 - How to control the turbocharged system and the turbocharged system - Google Patents

Description

The present disclosure relates to a turbocharged system and a control method for the turbocharged system.

Regarding the thrust bearing device that regulates the movement of the rotating shaft in the thrust direction applied to the turbocharger of an automobile, the refueling passage is branched into two refueling ports to regulate the movement of the rotating shaft in the thrust direction, and the hydraulic pressure is increased. (For example, see Patent Document 1).

International Publication No. 2014/038080

By the way, in a turbocharged supercharging system, it is known that the supercharging efficiency is improved by reducing the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing (hereinafter referred to as “clearance”) as much as possible. ..

In the turbocharged system, the movement of the rotating shaft in the thrust direction (axial direction) is restricted as in the technique described in Patent Document 1 above. Therefore, the clearance is set in consideration of deformation of the compressor impeller due to high-speed rotation and thermal expansion.

Therefore, the clearance is maximized at low rotation speeds and low temperatures, and there is a problem that the supercharging efficiency at low rotation speeds and low temperatures is lowered.

An object of the present disclosure is to provide a turbocharged system capable of improving the supercharging efficiency of the turbocharged system and a control method thereof.

The turbo supercharging system according to the embodiment of the present invention for achieving the above object includes a compressor arranged in the intake passage of the internal combustion engine, a turbine arranged in the exhaust passage of the internal combustion engine, and the compressor at one end. The compressor impeller is fixed, and the shaft to which the turbine impeller of the turbine is fixed at the other end, the sliding bearing that pivotally supports this shaft, and the supply device that supplies lubricating oil to the sliding bearing are provided. In the feeding system, the sliding bearing and the feeding device have two systems of hydraulic pipelines that are independent of each other, and when the pressure in one hydraulic pipeline becomes stronger than the pressure in the other hydraulic pipeline, the shaft is axially oriented. A distance acquisition device for acquiring the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing, and a control device connected to the distance acquisition device and the supply device are provided. Based on the distance acquired by the distance acquisition device, the control device adjusts the hydraulic pressure of the two hydraulic pipelines to determine the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing. The feature is that it is configured to control the holding in the range.

Further, the control method of the turbo type supercharging system according to the embodiment of the present invention for achieving the above object includes a compressor arranged in the intake passage of the internal combustion engine, a turbine arranged in the exhaust passage of the internal combustion engine, and a turbine. A shaft in which the compressor impeller of the compressor is fixed at one end and the turbine impeller of the turbine is fixed at the other end, a sliding bearing that pivotally supports the shaft, and a supply device that supplies lubricating oil to the sliding bearing. In the control method of the turbo type supercharging system including, the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing is acquired, and when the acquired distance deviates from a predetermined range, the sliding bearing and the said. The shaft is moved axially to make the hydraulic pressure of one of the two independent hydraulic pipelines formed in the feeder stronger than that of the other hydraulic pipeline. It is characterized in that the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing is maintained within the predetermined range.

According to the present disclosure, the supercharging efficiency of the turbocharged supercharging system can be improved.

It is a side view illustrating the embodiment of the turbocharging system. It is a figure which illustrates the slide bearing and the supply device. It is a figure which illustrates the slip plate of FIG. 2 in the X cross-sectional view. It is a figure which illustrates the control flow which shows the control method of the turbo type supercharging system.

Hereinafter, the turbocharged system 1 and the control method of the turbocharged system according to the embodiment of the present disclosure will be described with reference to the drawings.

As shown in FIG. 1, the turbocharged system 1 of the present embodiment includes a compressor 2, a turbine 3, a shaft 4, a slide bearing 5, and a supply device 6. The compressor 2 is a device arranged in the intake passage 7 of the engine (internal combustion engine) and compresses (supercharges) the intake air A flowing into the compressor 2 from the intake passage 7. The turbine 3 is a device that is arranged in the exhaust passage 8 of the engine and is rotationally driven by the energy of the exhaust gas G flowing into the turbine 3 from the exhaust passage 8. The shaft 4 is a device in which the compressor impeller 9 of the compressor 2 is fixed to one end thereof and the turbine impeller 10 of the turbine 3 is fixed to the other end thereof to transmit the rotational power of the turbine 3 to the compressor 2. The slide bearing 5 is a device that pivotally supports the shaft 4 and regulates the axial movement of the shaft 4. The supply device 6 is a device that supplies the lubricating oil O to the slide bearing 5.

The compressor impeller 9 is a member arranged inside the compressor housing 11 of the compressor 2, composed of a plurality of blade-shaped blades having the shaft 4 as a rotation axis, and attached to the outer periphery of the shaft 4. The compressor housing 11 is a member (housing) that constitutes the outer shape of the compressor 2 and includes various members such as the compressor impeller 9 inside the compressor housing 11. The turbine impeller 10 is a member arranged inside the turbine housing of the turbine 3, composed of a plurality of blade-shaped blades having the shaft 4 as a rotation axis, and attached to the outer periphery of the shaft 4. The turbine housing is a member (housing) that constitutes the outer shape of the turbine and includes various members such as the turbine impeller 10 inside the turbine housing.

In the present embodiment, as shown in FIG. 2, the slide bearing 5 and the supply device 6 have two hydraulic lines 12a and 12b that are independent of each other. The hydraulic line 12a is a hydraulic line near the turbine 3 side (one hydraulic line), and the hydraulic line 12b is a hydraulic line near the compressor 2 side. Further, the slide bearing 5 has a slide plate 13 and an oil discharge portion 14 inside the slide bearing 5. Further, the supply device 6 includes an oil control valve 15, a pump 16, and an oil tank 17.

The hydraulic pipe line 12a is a pipe line from the outlet of the oil control valve 15 on the turbine 3 side to the oil discharge portion 14 via the side surface of the slip plate 13 on the turbine 3 side. A part of the oil O passing through the hydraulic line 12a stays on the side surface on the turbine 3 side and applies an axial force on the compressor 2 side to the slip plate 13.

The hydraulic pipe line 12b is a pipe line from the outlet of the oil control valve 15 on the compressor 2 side to the oil discharge portion 14 via the side surface of the slip plate 13 on the compressor 2 side. A part of the oil O passing through the hydraulic line 12b stays on the side surface on the compressor 2 side and applies an axial force on the turbine 3 side to the slip plate 13.

When the pressure Pa of one hydraulic line 12a becomes stronger than the pressure Pb of the other hydraulic line 12b, the slide plate 13 moves to the side of the compressor 2 in the axial direction. As a result, the slide bearing 5 and the shaft 4 connected to the slide bearing 5 also move to the side of the compressor 2 in the axial direction. Further, when the pressure Pa of one hydraulic line 12a becomes weaker than the pressure Pb of the other hydraulic line 12b, the slide plate 13 moves to the turbine 3 side in the axial direction. As a result, the slide bearing 5 and the shaft 4 connected to the slide bearing 5 also move to the turbine 3 side in the axial direction.

The sliding plate 13 is a plate-shaped member that is connected to the shaft 4 and extends in a direction substantially perpendicular to the axial direction thereof. As shown in FIG. 3, the sliding plate 13 is formed with grooves 13a on both side surfaces in the axial direction thereof, and oil O that has passed through the oil control valve 15 passes through the grooves 13a on both side surfaces and is oil. It flows to the discharge part 14. The oil O passing through the grooves 13a on both side surfaces applies an axial force to the sliding plate 13. The oil discharge portion 14 is a portion formed in the housing of the slide bearing 5 and discharges the oil O that has passed through the hydraulic pipes 12a and 12b to the outside of the housing of the slide bearing 5. The oil control valve 15 is a device that is arranged outside the sliding bearing 5 and causes the oil O that has flowed into the oil control valve 15 from the pump 16 to flow out to either one hydraulic line 12a or the other hydraulic line 12b. be. The pump 16 is a device that is arranged outside the slide bearing 5 and pumps a part of the oil O stored in the oil tank 17 to the oil control valve 15. The oil tank 17 is a device arranged outside the slide bearing 5 to store oil O.

The turbocharged system 1 of the present embodiment is provided with a clearance sensor 18 as a distance acquisition device. The clearance sensor 18 is a device arranged on the inner wall 11a of the compressor housing 11 to acquire the distance d between the blade tip of the compressor impeller 10 and the inner wall 11a of the compressor housing 11. The clearance sensor 18 is preferably arranged so as to monitor the closest portion of the blade tip of the compressor impeller 10 and the inner wall 11a of the compressor housing 11 when the compressor impeller 10 is deformed. As a case where the compressor impeller 10 is deformed, a case where the rotation speed of the compressor impeller 10 is the upper limit and the thermal expansion thereof is the upper limit is exemplified. The upper limit means that the upper limit is intentionally set except at the time of failure.

As shown in FIGS. 1 and 2, the turbocharged system 1 of the present embodiment includes a control device 19. The control device 19 is hardware composed of a CPU that performs various information processing, an internal storage device that can read and write programs and information processing results used for performing the various information processing, and various interfaces. The control device 19 is electrically connected to various sensors such as a clearance sensor 18 and various devices such as a supply device 6 (oil control valve 15 and pump 16) via a signal line.

In the turbocharged system 1 of the present embodiment, the control device 19 adjusts the hydraulic pressures of the two hydraulic pipelines 12 based on the distance d acquired by the clearance sensor 18, respectively, and the blade tips of the compressor impeller 10 are used. And the control is performed to keep the distance d between the inner walls 11a of the compressor housing 11 within a predetermined range R.

The predetermined range R is a range in which the compressor impeller 10 does not come into contact with the inner wall 11a even if it is deformed due to high-speed rotation or thermal expansion, and the compressor impeller 10 has an upper limit of the rotational speed of the compressor impeller 10 and an upper limit of its thermal expansion. It is set based on the reference value dc, which is the distance between the blade tip and the inner wall 11a. The predetermined range R is a range represented by d1 <dc <d2, where the lower limit value is d1 and the upper limit value is d2. Each of the lower limit value d1 and the upper limit value d2 is a value set in consideration of a structural error, a measurement error of the clearance sensor 18, and the like with respect to the reference value dc. The reference value dc may be set as the value closest to the blade tip of the compressor impeller 10 and the inner wall 11a, and the reference value dc may be set as the lower limit value d1 of the predetermined range R (the predetermined range R is d1 =. Range represented by dc <d2).

The operation of the turbocharging system 1 in the present embodiment will be described. First, with respect to the flow rates Wa and Wb of the oil O passing through each of the two hydraulic pipelines 12a and 12b, both sides of the sliding plate 13 in the axial direction are regulated by the sliding bearing 5 in the axial movement of the shaft 4. Control (normal cooling control) is performed so that the bearing can be cooled appropriately. This normal cooling control is a control that is continuously performed during engine operation. By doing so, the sliding plate 13 is appropriately cooled by the oil O, and the axial movement of the shaft 4 is restricted.

Further, a reference value dc is set in advance in the control device 19 as a control target value. Then, the control device 19 controls to reduce this difference Δd (= | dc |) based on the difference between the distance d acquired by the clearance sensor 18 and the reference value dc. This control preferably sets the difference Δd to zero.

The control flow based on the turbocharged system 1 of the present embodiment will be described, in other words, an example of the control method of the turbocharged system will be described with reference to FIG. The control flow shown in FIG. 4 is a control flow that is periodically performed during the operation of the engine. It should be noted that this control flow is a control flow on the premise that the above-mentioned normal cooling control is performed.

When the control flow shown in FIG. 4 starts, the clearance sensor 18 acquires the acquired value d in step S10. Next, in step S20, it is confirmed whether or not the acquired value d of the clearance sensor 18 matches the reference value dc. In this step S20, if the acquired value d falls within the predetermined range R with respect to the reference value dc, it may be determined that they match, and in other cases, it may be determined that they do not match. If it is determined that they match (YES), the process proceeds to return and the control flow is terminated. If it is determined that they do not match (NO), the process proceeds to step S30.

In step S30, it is determined whether or not the acquired value d of the clearance sensor 18 is larger than the reference value dc (or a predetermined range R). If it is determined to be large (YES), the process proceeds to step S40, and if it is determined to be small (NO), the process proceeds to step S50. In step S40, the pressure Pa of one hydraulic line 12a is made stronger than the pressure Pb of the other hydraulic line 12b with respect to the two independent hydraulic lines 12a and 12b of the slide bearing 5 and the supply device 6. Then, the shaft 4 is controlled to move to the side of the compressor 2 in the axial direction. After performing step S40, the process proceeds to return and the present control flow is terminated. On the other hand, in step S50, the pressure Pa of one hydraulic line 12a is weakened from the pressure Pb of the other hydraulic line 12b, and the shaft 4 is controlled to move to the turbine 3 side in the axial direction. After performing step S50, the process proceeds to return and the present control flow is terminated.

From the above, according to the turbocharged system 1, the sliding bearing 5 has both sides in the axial direction so that the acquired value d of the clearance sensor 18 is within the predetermined range R regardless of the temperature of the compressor impeller 10. The flow rate of the oil O passing through each is adjusted independently of each other. As a result, the slide bearing 5 and the shaft 4 move in the axial direction so that the acquired value d is within the predetermined range R, so that the distance between the blade tip of the compressor impeller 10 and the inner wall 11a of the compressor housing 11 is reduced. It can be maintained in a state of high supercharging efficiency. As a result, the supercharging efficiency of the compressor 2 at low rotation speed or low temperature can be improved.

Further, by performing feedback control so that the difference between the acquired value d of the clearance sensor 18 and the reference value dc disappears, the acquired value d is set to a predetermined value even if the acquired value d deviates from the predetermined range R and the difference becomes large. It is preferable because it is easy to maintain within the range R. Instead of the clearance sensor 18, the compressor 2 is operated based on the operating state (engine rotation speed, supercharging pressure, fuel injection amount, etc.) of the engine on which the turbocharged supercharging system 1 is mounted as a distance acquisition device. An apparatus that monitors the state and predicts and calculates the acquired value d based on the operating state of the compressor 2 may be used. By using a device capable of predicting the acquired value d in this way, it is possible to move the shaft 4 by feedforward control and keep the predetermined value d within the predetermined range R.

Further, when the clearance sensor 18 monitors the portion where the blade tip of the compressor impeller 10 is closest to the inner wall 11a when the compressor impeller 10 is deformed, the clearance sensor 18 reliably avoids contact between the blade tip of the compressor impeller 10 and the inner wall 11a of the compressor housing 11. It is preferable because it can be used.

1 Turbo supercharging system 2 Compressor 3 Turbine 4 Shaft 5 Sliding bearing 6 Supply device 7 Intake passage 8 Exhaust passage 9 Compressor impeller 10 Turbine impeller 11 Compressor housing 11a Compressor housing inner wall 12 Hydraulic pipeline 12a One hydraulic pipeline 12b The other Hydraulic pipeline 13 Sliding plate 14 Oil discharge part 15 Oil control valve 16 Pump 17 Oil tank 18 Clearance sensor (distance acquisition device)
19 Control device

Claims (4)

A compressor arranged in an intake passage of an internal combustion engine, a turbine arranged in an exhaust passage of the internal combustion engine, a compressor impeller of the compressor fixed to one end, and a turbine impeller of the turbine fixed to the other end. In a turbocharged system including a shaft, a sliding bearing that pivotally supports the shaft, and a supply device that supplies lubricating oil to the sliding bearing.
The sliding bearing and the supply device have two hydraulic lines that are independent of each other, and the shaft moves in the axial direction when the pressure of one hydraulic line becomes stronger than the pressure of the other hydraulic line. And
A distance acquisition device for acquiring the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing, and a control device connected to the distance acquisition device and the supply device are provided.
Based on the distance acquired by the distance acquisition device, the control device adjusts the hydraulic pressure of the two hydraulic pipelines to determine the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing. A turbocharged supercharging system characterized by being configured to control the pressure within the range of. The predetermined range is set based on a reference value which is a distance between the blade tip of the compressor impeller and the inner wall of the compressor housing when the rotation speed of the compressor impeller is the upper limit and the thermal expansion is the upper limit.
The turbocharged system according to claim 1, wherein the control to be held is a control for reducing the difference based on the difference between the distance acquired by the distance acquisition device and the reference value. The distance acquisition device according to claim 1 or 2 monitors the closest portion of the blade tip of the compressor impeller and the inner wall of the compressor housing when the rotation speed of the compressor impeller is the upper limit and the thermal expansion is the upper limit. The turbocharged system described. A compressor arranged in the intake passage of the internal combustion engine, a turbine arranged in the exhaust passage of the internal combustion engine, a compressor impeller of the compressor fixed to one end, and a turbine impeller of the turbine fixed to the other end. In a method of controlling a turbocharged system including a shaft, a sliding bearing that pivotally supports the shaft, and a supply device that supplies lubricating oil to the sliding bearing.
Obtain the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing.
When the acquired distance deviates from a predetermined range, the hydraulic pressure of one of the two hydraulic pipelines formed in the sliding bearing and the supply device and independent of each other is transferred to the other hydraulic pipe. A turbocharged supercharger characterized in that the shaft is moved axially to be stronger than the hydraulic pressure of the road to keep the distance between the blade tip of the compressor impeller and the inner wall of the compressor housing within the predetermined range. How to control the system.

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